How to truncate the Slow Query Log on AWS RDS MySQL

-

I was in need to empty the slow_log table in MySQL database inside a Amazon Relational Database System to look into a performance issue. But I got the below error. I was surprised because I had login with the master user of the RDS.

mysql> use mysql

mysql> truncate table slow_log

Error Code: 1044. Access denied for user 'dbroot'@'%' to database 'mysql'

On surfing the internet I got this and it resolved my problem.

"Amazon RDS will not give you SSH access to its database server. That means you don’t have the opportunity to view any of the log files, even the slow query log, for the database. But RDS provides a way to play with the slow queries.

If your slow queries are many then this table will hold too many queries to handle. You cannot truncate the table or delete any row from there. There is only a way to move all the data from this table to another table named ‘slow_log_backup’, making the slow_log table empty. To do so you have to run a stored procedure already available in RDS.

Select the ‘mysql’ database and you can see some stored procedure listed. Run the procedure named ‘rds_rotate_slow_log’ by running CALL mysql.rds_rotate_slow_log command.

In the back-end RDS just renames those two tables, it does not actually move the data. Running the command twice will delete the slow log completely from the database server."


Excerpt from show tables

| slow_log                      |

| slow_log_backup               |


You can view the definition of the procedure by using the show create procedure ... statement.

For example: show create procedure mysql.rds_rotate_slow_log\G

Comments

Post a Comment

Back To Top

Popular posts from this blog

error 18 at 0 depth lookup: self signed certificate

-
I was trying to test SSL connection between MySQL client and server. For that I created SSL certificate and keys by following the MySQL documentation at: Creating SSL Certificates and Keys Using openssl After finishing up all the commands when I verify the certificates by using: openssl verify -CAfile ca.pem server-cert.pem client-cert.pem I got the following output: error 18 at 0 depth lookup : self signed certificate error server-cert.pem: verification failed client-cert.pem: OK  Reason : The Common Name value used for the server and client certificates/keys must each differ from the Common Name value used for the CA certificate. Otherwise, the certificate and key files will not work for servers compiled using OpenSSL. Solution : When OpenSSL prompts you for the Common Name for each certificate, use different names. Common Name (e.g. server FQDN or YOUR name) []: I used values as follows: CA Cert:  ssl-ca-cert Server Cert: ssl-ca-server-cert Client Cert:  ssl-c
Read more

How to check fragmentation in MySQL tables

-
MySQL tables, including MyISAM and InnoDB, two of the most common types, experience fragmentation as data is inserted, updated and deleted randomly. Fragmentation can leave large holes in your table, blocks which must be read when scanning the table. Optimizing your table can therefore make full table scans and range scans more efficient. We will mention how to check fragmentation in MySQL tables using SQL queries. USE < put_your_dbname_here > SELECT TABLE_NAME, CONCAT(ROUND(( data_length + index_length ) / ( 1024 * 1024 ), 2), 'M') TOTAL_SIZE, CONCAT(ROUND(( DATA_FREE ) / ( 1024 * 1024 ), 2), 'M') DATA_FREE FROM information_schema.TABLES where table_schema = database() and ROUND(( DATA_FREE ) / ( 1024 * 1024 ), 2) > 0.00 ORDER BY DATA_FREE DESC; SELECT TABLE_NAME, ROUND(((Data_length - (TABLE_ROWS * Avg_row_length))/Data_length) * 100, 2) FRAG_Percent FROM information_schema.TABLES where table_schema = database() and TABLE_ROWS > 0
Read more

How to Drop or Remove or Decommission a Database in Oracle

-
How to Drop or Remove or Decommission a Database in Oracle Database Decommission steps for Oracle 10G and 11g databases Note: ~~~~~~~~ Every organization has its own documented way of removing or decommissioning the active/running database that is supporting an Enterprise’s Application. Here I am presenting some general steps which may coincide with your organization’s standard operation procedure (SOP). 1)   Please get the required approval from Business/Customer to proceed for database decommissioning. 2)   Send the Notification to Business/Customer that we are going to decommission the database. (if required) 3)   Raise a Request for Storage and Backup team to take the required backup (provide all the details in the raised request) and to keep the Backup for a specified period of time, say for next 2 years, (That is called the backup retention period). Retention Period may be varied based on your business needs and SLA. The backup can be on disk or
Read more